The main symptom of epilepsy is repeated seizures. These are sudden bursts of electrical activity in the brain that temporarily affect how it works.

Seizures can affect people in different ways, depending on which part of the brain is involved.

Some seizures cause the body to jerk and shake (a "fit"), while others cause problems like loss of awareness or unusual sensations. They typically pass in a few seconds or minutes.

Seizures can occur when you're awake or asleep. Sometimes they can be triggered by something, such as feeling very tired.